Swarms are dense masses of Fine, Diminutive, or Tiny creatures that would not be particularly dangerous in small groups, but can be terrible foes when gathered in sufficient numbers. For game purposes a swarm is defined as a single creature with a space of 10 feet-gigantic hordes are actually composed of dozens of swarms in close proximity. A swarm has a single pool of Hit Dice and hit points, a single initiative modifier, a single speed, and a single Armor Class. It makes saving throws as a single creature.

A large swarm is completely shapeable, though it usually remains contiguous. (implemented as EffectCutsceneGhost and immunity to knockdown)

In order to attack, a single swarm moves into opponents’ spaces, which (might cos absence of tumble) provoke an attack of opportunity. It can occupy the same space as a creature of any size, since it crawls all over its prey, but remains a creature with a 10-foot space. Swarms never make attacks of opportunity, but they can provoke attacks of opportunity. (A builder can set variable to allow swarm creature to attack, without that, they are only following theirs prey and cause damage from heartbeat script)

Swarms are extremely difficult to fight with physical attacks (100% immunity to physical damage means they are immune to the sneak attack too). However, they have a few special vulnerabilities, as follows:
- A lit torch swung as an improvised weapon deals 1d3 points of fire damage per hit.
- A weapon with a special ability such as flaming or frost deals its full energy damage with each hit, even if the weapon’s normal damage can’t affect the swarm.
- A lit lantern can be used as a thrown weapon, dealing 1d4 points of fire damage to all creatures in squares adjacent to where it breaks.
(vulnerabilities aren't implemented! The swarm traits are implemented as supernatural effect to save up resources so the creatures can use skin for the racial type such as vermin properties.)

Swarms usualy also distract their prey causing nauseate for 1round (fort save negates). (implemented as daze effect with green glow, that however means that mind spells immunity negates this effect, which shouldn't)

INSTALLATION:

You need to incorporate the files inside files folder into your module. Put the content either into override or into haks, and in case you use custom content do not forget to merge 2DAs.
Then import included erf into your module and thats it. The functionality depends solely on the 2DA merging process. If you relocate lines in vfx_persistent.2da or appearance.2da you need to adjust blueprints and scripts to reflect this. If you have any troubles contact me, but no I won't make CEP/whatever compatible version.

USAGE:

There are six predefined creatures are listed in custom palette under insect/beetles:
Locust Swarm, CR 4: 1d6 swarm damage, distraction DC 12, ultravision, vermin race (mind immunity)
Itchies Swarm, CR 5: 2d6 swarm damage, disease (vermin madness), distraction DC 14, ultravision, vermin race
Mosquito Swarm, CR 6: 2d6 swarm damage, distraction DC 14, ultravision, vermin race
Black Locust Swarm, CR 7: 3d6 swarm damage, disease (vermin madness), distraction DC 16, ultravision, vermin race
Plague Bugs Swarm, CR 8: 3d6 swarm damage, disease (mummy rot), distraction DC 16, ultravision, vermin race
Hellwasp Swarm, CR 9: 3d6 swarm damage, poison (giant wasp), distraction DC 18, ultravision, mindless (immunity to mind spells), fire resist 10, soak 10/+1, magical beast race

All these swarm creatures are treated as flying bugs (because of visual effect) and thus they have a variable FLYING set to 1 which in community patch makes them immune to certain spell and spellabilities namely grease and spike growth.

These blueprints are only a showcase for builder to start with, its easy and recommended to make your own swarm creatures. See readme inside archive for details. The scripting allows to make a swarm with curse, level drain, blindness, stun, paralysis, poison, disease, distraction special abilities, with any damage per round and more. Its even possible to make a stationary swarms that guards a 10m circle grid and won't follow intruders beyond this border.